模拟海洋大气环境下PCB-HASL的腐蚀行为与机理  

Corrosion Behavior and Mechanism of PCB-HASL in Simulated Marine Atmospheric Environment

作　　者：战贵盼 韩永恒 谭晓明 丛凯 赵仁杰 ZHAN Gui-pan;HAN Yong-heng;TAN Xiao-ming;CONG Kai;ZHAO Ren-jie(Military Representative Office of the Ministry of Naval Equipment in Beijing,Beijing 100074,China;Qingdao Branch of Naval Aeronautical University,Shandong Qingdao 266041,China)

机构地区：[1]海装驻北京地区军事代表局,北京100074 [2]海军航空大学青岛校区,山东青岛266041

出　　处：《表面技术》2022年第5期245-253,303,共10页Surface Technology

摘　　要：目的基于舰载机服役海洋环境,针对热风整平无铅喷锡印制电路板(Hot Air Solder Level Printed Circuit Board,PCB-HASL)开展加速腐蚀试验研究,揭示其腐蚀机理,表征其宏/微观腐蚀电化学行为。方法根据实测的服役海洋大气环境数据,基于编制的加速腐蚀试验环境谱,针对PCB-HASL开展了加速腐蚀试验。采用电化学工作站测试不同腐蚀周期试样的极化曲线和电化学阻抗谱,表征了腐蚀电化学机理和宏观电化学特性。采用扫描Kelvin探针技术测试了不同腐蚀周期试样表面Kelvin电位分布特征,表征了微区电化学特性。结果腐蚀第6周期时,PCB-HASL的绝缘电阻大幅度衰减,达到失效临界状态;第0~2周期,自腐蚀电流密度由1.43μA/cm^(2)陡增至3.97μA/cm^(2),腐蚀速率快速增大,局部区域诱发腐蚀;第2~3周期,自腐蚀电流密度降低,腐蚀速率降低;第3~4周期,自腐蚀电流密度稍有增大,腐蚀速率稍微增加,腐蚀产物局部发生脱落;第4~7周期,自腐蚀电流密度减小,在第7周期达到最小,为0.55μA/cm^(2),相比第2周期降低了86%,呈明显的均匀腐蚀特征。Kelvin电位分布和电荷转移电阻的倒数(1/R_(ct))随加速腐蚀试验周期的变化规律与自腐蚀电流密度的变化规律相吻合。结论PCB-HASL的腐蚀速率随加速试验周期大致呈增大—减小—小幅增大—减小的变化规律,由初期的局部区域腐蚀逐渐转变为后期的均匀腐蚀,在表面形成较为致密的腐蚀产物层,使得腐蚀速率大大降低。Based on the marine environment of Shipborne aircraft in service,the accelerated corrosion test was carried out for hot air leveling lead-free tin sprayed printed circuit board(PCB-HASL),which revealed the corrosion mechanism and characterized the macro/micro corrosion electrochemical behavior.According to the measured marine atmospheric environment data,based on the prepared accelerated corrosion test environment spectrum,the accelerated corrosion test was carried out for PCB-HASL.The polarization curve and electrochemical impedance spectroscopy of samples with different corrosion cycles were measured by electrochemical workstation,and the corrosion electrochemical mechanism and macro electrochemical characteristics were characterized;Scanning Kelvin probe technique was used to measure the distribution characteristics of Kelvin potential on the surface of samples with different corrosion cycles,and the micro area electrochemistry characteristics were characterized.During the 6^(th) cycle of corrosion,the insulation resistance of PCB-HASL decreases greatly and reaches the critical state of failure;In cycle 0^(th)-2^(nd),the self corrosion current density increased from 1.43μA/cm^(2) increased sharply to 3.97μA/cm^(2),the corrosion rate increases rapidly and corrosion is induced in local areas;In the 2^(nd)-3^(rd) cycle,the self corrosion current density decreases and the corrosion rate decreases;In the 3^(rd)-4^(th) cycle,the self corrosion current density increased slightly,the corrosion rate increased slightly,and the corrosion products fell off locally;In the 4^(th)-7^(th) cycle,the self corrosion current density decreases and reaches the minimum in the 7^(th) cycle,which is 0.55μA/cm^(2),decreased by 86%compared with the second cycle,showing obvious uniform corrosion characteristics.The variation law of Kelvin potential distribution and reciprocal of charge transfer resistance(1/R_(ct))with the accelerated corrosion test cycle is consistent with the variation law of self corrosion current density.The corro

关 键 词：海洋环境 PCB-HASL 微区电化学 扫描Kelvin探针技术 电化学阻抗谱 腐蚀行为和机理 

分 类 号：TG174.4[金属学及工艺—金属表面处理] TB37[金属学及工艺—金属学]